Contact breaker for ignition distributors



Nov. 3, 1964 A. BAROZZI 3,155,784.

CONTACT BREAKER FOR IGNITION DISTRIBUTORS Filed July 21. 1960 INVENTOR. ALBERTO BAROZZI BY Jam United States Patent 3,155,784 CONTACT BREAKER FUR IGNITEON DISTRIBUTORS Alberto Barozzi, Sesto San Giovanni, Italy, assignor to Fahbrica ltaliana Magneti Marelli S.p.A., Milan, Italy, a corporation of Italy Filed July 21, 1960, Ser. No. 44,352 Claims priority, application Italy, Aug. 3, 1959, 13,031/59 4 Claims. (Cl. 200-60) The present invention relates to improvements in contact breakers for ignition systems, and more particularly to a contact breaker for the ignition coil of a high tension ignition system for internal combustion engines.

It is commonly known, that normal contact breaker devices employed at present are excessively noisy.

It has been ascertained that the noise thus produced in present day ignition contact breakers by the intermittent engagement thereof with the moving cam is due to the fact that the cam engaging shoe is rigidly attached to the distributor arm. The present invention is intended to eliminate or greatly reduce the noise created by the intermittent engagement of the rigid shoe with the actuating cam.

In accordance with the present invention said defect is obviated and eliminated by installing the collector shoe on the breaker arm in a cantilever fashion in such a manner as to give the collector shoe a sufficient degree of elasticity without compromising or impairing the efficiency of the apparatus as far as the rapidity of opening and closing of the contacts is concerned.

Other objects and advantages of the invention will becomeapparent during the course of the following description of the accompanying drawing in which FIG- URE 1 is a side elevational view illustrating the manner in which the collector shoe is attached to the distributor arm.

FIGURE 2 is a side elevational view of the distributor arm similar to FIGURE 1 but showing the end of the collector shoe bent at an acute angle.

FIGURE 3 is a side elevational view similar to FIG- URES l and 2, but showing the collector shoe as in FIGURE 1 with the distributor arm having its end portion slightly bent in a direction away from the collector shoe.

FIGURE 4 is a side elevational view of the distributor arm showing portions thereof in section and broken away to illustrate the manner in which the collector shoe is yieldingly attached to the distributor arm, and

FIGURE 5 is a side elevational view of a modified form of the invention showing a portion of the distributor arm broken away and in section to illustrate the manner in which the collector shoe is yieldingly attached to the distributor arm.

In the drawing, and more in detail, attention is directed to FIGURE 1 wherein the numeral 1 will be employed to generally designate a rotary distributor or breaker arm having a moving contact 2 on one end thereof and a rotation journal or hearing opening 3 for receiving the conventional stud on a distributor housing (not shown). A yielding return spring member 4 has a terminal portion 4' secured to the distributor arm I by means of a suitable fastener such as a rivet or the like.

In FIGURE 1, the collector shoe 5' is made of insulating material preferably a Bakelite treated cloth and is shaped in the form of an L with the longer leg 5 attached to the back 1' of the distributor arm and the other end as at 5 extending at right angles thereto. A small plate 6 in the form of a Washer or the like and formed of Bakelite coated cloth is interposed between the plate portion 1' of the distributor arm and the collector shoe 5'.

3,155,?84 Patented Nov. 3, 1964 "ice The plate 6 may be in the form of a washer or the like with a length or diameter smaller than that of the collector shoe so that the front part of the collector shoe projects therebeyond and is spaced away from the distributor arm in a cantilever fashion. The method of attaching or aflixing the collector shoe to the rotor arm is effected by commonly known fastener means.

The invention shown in FIGURE 2 is slightly different from that shown in FIGURE 1. The breaker arm 1, contact 2, bearing 3 and spring 4 are all similar, but the collector shoe 5 has its bent end portion 5 extending at an acute angle along the line 77 to the portion 5. The axis 7 of the nose passes by the center of the driving cam (not shown).

In the form of the invention shown in FIGURE 3 the rotor or breaker arm 5 are substantially the same as shown in FIGURE 1 with the exception that the free end of the arm 1 is slightly bent upwardly to permit a slight amount of elasticity between the collector shoe 5 at the free end thereof in such a manner that the front part of the collector shoe as shown in the drawing is arranged in a cantilever fashion without requiring the interposition of the small placing plate 6 shown in FIGURE 1 and disposed between the long leg 5 and the back of the breaker arm I.

In the form of the invention shown in FIGURE 4, the collector shoe 5 is attached to the free extremity 4 of a continuation of the spring member 4 which is secured to the back I of the breaker or rotor arm from the underside as at 6. The back 1' is provided with an opening 8 to prevent the collector shoe attaching means from contacting the back I of said breaker arm.

In the modified form of the invention shown in FIG- URE 5 the breaker arm 1 and contact 2 are similar to those shown in FIGURES l to 4 inclusive, with the exception that the collector shoe is not spaced there-from. In this form of the invention the spring member 4 is provided with an extended terminal portion 4' which is directly attached to the back of the rotor or breaker arm. The free extremity of said terminal extends through an opening 9 in the rotor or breaker arm and is secured to the collector shoe 5. Over and above this the hole 9 allows cantilever oscillation of the collector shoe 5.

I claim:

1. In a contact breaker for ignition distributors for internal combustion engines, a distributor rotor arm, a hearing at one end of said arm adapted to be received on the bearing pin of said distributor, a contact on the free end of said arm adapted to engage a contact on said distributor, an L-shaped collector shoe formed of flexible insulating material having a short leg section and a long leg section with the long leg section attached to said arm intermediate its length and between said bearing and contact, and washer plate means interposed between the rotor arm and collector shoe permitting yielding movement of said shoe with respect to said arm in a cantilever fashion.

2. In a contact breaker for ignition distributors for internal combustion engines, comprising a distributor rotor arm, a bearing formed at one end of said arm adapted to be received on a bearing pin on said distributor, a contact on the free end of said arm to engage the fixed contact of said distributor, an Lshaped collector shoe formed of insulating material having a short leg portion and a long leg section with the :long leg sect-ion attached to said arm intermediate the bearing and contact, the short leg section of said collector shoe forming a rotor engaging portion offset from the point of contact from the point of attachment and a washer plate member interposed between said rotor arm and collector shoe permitting yielding movement of said shoe.

3. In a contact breaker for ignition distributors in internal combustion engines, a distributor rotor arm, a bearing at one end of said arm to be received on a bearing pin of said distributor, a contact on the free swinging end of said arm, a collector shoe of L-shaped construction formed of insulating material forming long and short leg sections with its longer leg section attached to said rotor arm intermediate its length and between said bearing and contact, a Washer plate interposed between the rotor arm and the end of said longer leg of said collector shoe, and means for attaching said shoe to said arm, the shorter leg of said shoe forming a cam rotor contacting portion offset from the point of attachment to permit yielding action of said shoe with respect to said arm.

4. in a contact breaker for ignition distributors on internal combustion engines, a distributor rotor arm, a bearing formed at one end of said arm adapted to be received on a bearing pin on said distributor, a contact on the free end of said arm engageable with the contact on said distributor, a collector shoe of L-shaped construction formed of insulating material providing short and long leg sections, a yielding metal spring member having one end attached to said long section of said shoe, means for connecting the other end of said spring member to the back of said rotor arm in spaced relation therefrom and with the short leg of said shoe offset from the point of attachment of said spring member to permit yielding cantilever action with respect to said arm.

References (Iited by the Examiner UNITED STATES PATENTS 1,189,870 7/16 Rhoades 2GO3() 2,416,655 2/47 Thomas 2003O 2,847,524 8/50 Slick 200-30 2,635,150 4/53 Spang ZOO-30 2,769,044 10/56 Russell 200-3O 2,939,337 6/60 SWeger 200- 19 BERNARD A. GILHEANY, Primary Examiner.

20 MAX L. LEVY, ROBERT K. SCHAEFER, Examiners. 

1. IN A CONTACT BREAKER FOR IGNITION DISTRIBUTORS FOR INTERNAL COMBUSTION ENGINES, A DISTRIBUTOR ROTOR ARM, A BEARING AT ONE END OF SAID ARM ADAPTED TO BE RECEIVED ON THE BEARING PIN OF SAID DISTRIBUTOR, A CONTACT ON THE FREE END OF SAID ARM ADAPTED TO ENGAGE A CONTACT ON SAID DISTRIBUTOR, AN L-SHAPED COLLECTOR SHOE FORMED OF FLEXIBLE INSULATING MATERIAL HAVING A SHORT LEG SECTION AND A LONG LEG SECTION WITH THE LONG LEG SECTION ATTACHED TO SAID ARM INTERMEDIATE ITS LENGTH AND BETWEEN SAID BEARING AND CONTACT, AND WASHER PLATE MEANS INTERPOSED BETWEEN THE ROTOR ARM AND COLLECTOR SHOE PERMITTING YIELDING MOVEMENT OF SAID SHOE WITH RESPECT TO SAID ARM IN A CANTILEVER FASHION. 